Positive feed powder dispenser



Oct. 13, 1964 J. w. Ross 3,152,733

POSITIVE FEED POWDER DISPENSER Filed April 23, 1962 jaw IN VEN TOR. JOHN W.R0 $S lzw/wmx anada Filed Apr. 23, 1962, Ser. No. 189,512 .(Ilairns. (@l. 222-193) This invention relates to positive feed powder dispensers, and more particularly, for metering powder from'a pressurized hopper and dispensing the powder in a gas borne stream.

There is an ever-increasing list of demands for powder dispensing such as for powder lancing, powder cutting, powder scarfing, furnace feed applications and many others. The composition of the powder materials being dispensed varywidely, from pure iron powder to ironaluminum mixtures, carbide graphite mixtures, iron ore mixtures, etc. As the applications increase, the conditions under which they may operate become more critical. Thev cost of the equipment must be kept as low as possible, the capacity of the unit must be as high as possible to avoid frequent stoppages to refill the hopper, the range of flows must be as" wide as possible to extend the applications on which a single unitmay be used, and above all,it must be possible to accurately preset the flow rate of' the powder. For instance, on scarfing operations, the volume of scarfing powdernecessary for a certain depth of steel removal can be calculated. A

rapid change'of powder flow is essential for economic operation to meet the requirements of various operations. .The main objects of the present invention are to statisfy these demands.

The flow of powder onto the roller is controlled by a tubular nylon or wear-resistant plastic follower which is spring loaded and shaped on the end to press firmly on the slotted roller. Thus, the only powder that is allowed to pass is that which is picked up in the slots as the roller rotates and'is deposited by gravity as the rotation continues. The powder which passes the roller is forced out the delivery line by air pressure. The system is pressure equalized so the powder will not tend to flow the wrong way.

In the drawings:

FIG. 1 is an elevation'of a hopper provided with a powder dispenser according to the preferred embodiment of the present invention;

FIG. 2 is an enlarged vertical section through the dispenser shown in FIG. 1;

FIG. 3 is a vertical section taken along the line 3-3 of FIG. 2; and T FIG. 4 is plan of the shroud shown in FIGS. 2 and 3.

As shown in FIG. 1, the powder to be, dispensed is charged into a hopper through a charging opening closed by a screw clamped lid 12, and gas under press'ur'eis supplied to the system by a line 14. The bottom of the hopper is connectedto a metering dispenser 15.

As shown in FIG. 2, the dispenser is formed by 1 United States Patent 0 the flanged outlet of the hopper'll). A rotor 24 is journaled in the body 15 on an axis transverse to the bore 20 and extending into the metering chamber 16. The rotor has axially extending grooves 26 in the periphery thereof. The side walls of these grooves are preferably radial, with a rounded lower surface forming the bottom of the groove.

A tubular liner 28 is slidably mounted in the bore 20 above the rotor 24. The outlet end at the bottom of the lever 28 is shaped to fit the upper portion of the periphery of the grooved rotor 24 to control the flow of powder into the grooves 26. A helical coil spring 30 is mounted in the feed bore 18 engaging the top of the liner 28 to urge the bottom of the liner into pressure contact with the groovedrotor 24. A sleeve 32 is fitted inside the spring 30 above the liner to prevent powder clogging the spring. A stainless steel roller and a nylon follower have been found to be the best combination where fairly abrasive powders are concerned. There are no doubt many applications where a nylon or plastic roller would be quite suitable.

Rigidly mounted in the body 15 is a shroud 34 surrounding the lower end of the liner 28 above the rotor 24. In the formshown, the shroud is' a rectangular block'having a lower surface grooved to fit upper portion of the rotor and extending axially thereof from the the ends of the grooves, concentric disks 36 are secured on each end of the rotor 24.

As shown in FIG. 3, extending into the meteringchamber 16 is an air booster jet 38 to take the powder fed by the rotor and convey it in suspension through the delivery bore 40, and attached hose line to the use point. As shown in FIG. 1, a pressure equalizer tube 42 is connected from the top of the hopper 10 to the metering chamber 16 to prevent backflow of' the powdered material. As shown in FIG. 2, the rotor is preferably driven by an air motor M, for driving the rotor from the same source of pressure as the powder supply.

What is claimed is:

1.. Powder dispenser comprising a body having a metering chamber therein with a substantially vertical feed bore above said chamber having an inlet end receiving powder'from a pressurized source of supply, and a delivery bore below said chamber for discharging pressurized powder from said chamber, a rotor journaled in said body on an axis transverse to said feed bore and extending into said meteringschamber below said feed bore and having axially extending metering grooves in the periphery thereof, said feed bore having an enlarged lower portion, a sleeve having an upper portion secured in said lower portion and depending therebelow, and a tubular liner slidably mounted in said feed bore above said grooved rotor and slidable on the outside of the lower portion of said sleeve and having an outlet end fitting the upper portion of the periphery of said grooved rotor to control the flow. of powder into said grooves.

a casting cored to form a metering chamber 16 which is closed by a pressure-tight cover 18. The body 15 hasan upstanding pipe or elongated boss with a substantiallyvertical bore 29 connected by a gland 22 to 2. Powder dispenser comprising a body having a meter-, ing chamber therein with. a substantially vertical feed Q bore above said chamber having an inlet end receiving powder from a pressured source of supply, and .a delivery bore below said chamber for discharging pressurized powder from said chamber, a sleeve mounted in said feed let end fitting the upper portion of the periphery of said grooved rotor, and a helical coil spring in said feed bore outside of said sleeve engaging the top of said liner for urging the bottom of said liner into pressure contact with said grooved rotor.

3. Powder dispenser comprising a body having a meter ing chamber therein with a substantially vertical feed :bore above said chamber having an inlet end receiving powder from a pressurized source of supply, and a delivery bore below said chamber for discharging pressurized powder from said chamber, a rotor journaled in said body on an axis transverse to said feed bore and extending into said metering chamber below said feed bore and having axially extending metering grooves in the .periphery thereof, a tubular liner slidably mounted in said bore above said grooved rotor, and a shoud surrounding the lower end of said liner above said rotor having a bottom fitting the upper portion of said rotor and extending axially thereof from said liner to the ends of said rotor for closing the upper portion of said grooves outside of said liner.

4. Powder dispenser comprising abody having a meter- :ing chamber therein with a substantially vertical feed bore above said chamber having an inlet end receiving powder from a pressurized source of supply, and a de- "extending 'into said metering chamber below said feed bore-andhaving axiallyextending metering grooves in the periphery thereof, a tubular liner slidably mounted in said bore above said gg'rooved rotor and havingan outlet end fitting the upper portion of the periphery of said grooved rotor to control the flow of powder into said grooves, and an air motor for driving said rotor from the same source of pressure as said powder supply.

5. Powder dispenser comprising a body having a metering chamber therein with a substantially vertical feed bore above said chamber having an inlet end receiving powder 'from a pressurized source of supply, and a delivery bore below said chamber for discharging pressurized powder from said chamber, a rotor journaled in said body on an axis transverse to said feed bore and extending into said metering chamber below said feed bore and having axially extending metering grooves in the periphery thereof, concentric disks secured on each end of said rotor for closing the ends of said grooves, and a tubular liner slidably mounted in said bore above said grooved rotor and having an outlet end fitting the upper portion of the periphery of said grooved rotor to control the flow'of powder into said grooves.

Germany June 22, 

1. POWDER DISPENSER COMPRISING A BODY HAVING A METERING CHAMBER THEREIN WITH A SUBSTANTIALLY VERTICAL FEED BORE ABOVE SAID CHAMBER HAVING AN INLET END RECEIVING POWDER FROM A PRESSURIZED SOURCE OF SUPPLY, AND A DELIVERY BORE BELOW SAID CHAMBER FOR DISCHARGING PRESSURIZED POWDER FROM SAID CHAMBER, A ROTOR JOURNALED IN SAID BODY ON AN AXIS TRANSVERSE TO SAID FEED BORE AND EXTENDING INTO SAID METERING CHAMBER BELOW SAID FEED BORE AND HAVING AXIALLY EXTENDING METERING GROOVES IN THE PERIPHERY THEREOF, SAID FEED BORE HAVING AN ENLARGED LOWER PORTION, A SLEEVE HAVING AN UPPER PORTION SECURED IN SAID LOWER PORTION AND DEPENDING THEREBELOW, AND A TUBULAR LINER SLIDABLY MOUNTED IN SAID FEED BORE ABOVE SAID GROOVED ROTOR AND SLIDABLE ON THE OUTSIDE OF THE LOWER PORTION OF SAID SLEEVE AND HAVING AN OUTLET END FITTING THE UPPER PORTION OF THE PERIPHERY OF SAID GROOVED ROTOR TO CONTROL THE FLOW OF POWDER INTO SAID GROOVES. 